sql_db.cc 47.8 KB
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/* Copyright (C) 2000-2003 MySQL AB
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   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.
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   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
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   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */


/* create and drop of databases */

#include "mysql_priv.h"
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#include <mysys_err.h>
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#include "sp.h"
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#include "events.h"
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#include <my_dir.h>
#include <m_ctype.h>
#ifdef __WIN__
#include <direct.h>
#endif

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#define MAX_DROP_TABLE_Q_LEN      1024

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const char *del_exts[]= {".frm", ".BAK", ".TMD",".opt", NullS};
static TYPELIB deletable_extentions=
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{array_elements(del_exts)-1,"del_exts", del_exts, NULL};
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static long mysql_rm_known_files(THD *thd, MY_DIR *dirp,
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				 const char *db, const char *path, uint level, 
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                                 TABLE_LIST **dropped_tables);
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static long mysql_rm_arc_files(THD *thd, MY_DIR *dirp, const char *org_path);
static my_bool rm_dir_w_symlink(const char *org_path, my_bool send_error);
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/* Database lock hash */
HASH lock_db_cache;
pthread_mutex_t LOCK_lock_db;
int creating_database= 0;  // how many database locks are made


/* Structure for database lock */
typedef struct my_dblock_st
{
  char *name;        /* Database name        */
  uint name_length;  /* Database length name */
} my_dblock_t;


/*
  lock_db key.
*/

static byte* lock_db_get_key(my_dblock_t *ptr, uint *length,
                             my_bool not_used __attribute__((unused)))
{
  *length= ptr->name_length;
  return (byte*) ptr->name;
}


/*
  Free lock_db hash element.
*/

static void lock_db_free_element(void *ptr)
{
  my_free((gptr) ptr, MYF(0));
}


/*
  Put a database lock entry into the hash.
  
  DESCRIPTION
    Insert a database lock entry into hash.
    LOCK_db_lock must be previously locked.
  
  RETURN VALUES
    0 on success.
    1 on error.
*/

static my_bool lock_db_insert(const char *dbname, uint length)
{
  my_dblock_t *opt;
  my_bool error= 0;
  DBUG_ENTER("lock_db_insert");
  
  safe_mutex_assert_owner(&LOCK_lock_db);

  if (!(opt= (my_dblock_t*) hash_search(&lock_db_cache,
                                        (byte*) dbname, length)))
  { 
    /* Db is not in the hash, insert it */
    char *tmp_name;
    if (!my_multi_malloc(MYF(MY_WME | MY_ZEROFILL),
                         &opt, (uint) sizeof(*opt), &tmp_name, length+1,
                         NullS))
    {
      error= 1;
      goto end;
    }
    
    opt->name= tmp_name;
    strmov(opt->name, dbname);
    opt->name_length= length;
    
    if ((error= my_hash_insert(&lock_db_cache, (byte*) opt)))
    {
      my_free((gptr) opt, MYF(0));
      goto end;
    }
  }

end:
  DBUG_RETURN(error);
}


/*
  Delete a database lock entry from hash.
*/

void lock_db_delete(const char *name, uint length)
{
  my_dblock_t *opt;
  safe_mutex_assert_owner(&LOCK_lock_db);
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  if ((opt= (my_dblock_t *)hash_search(&lock_db_cache,
                                       (const byte*) name, length)))
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    hash_delete(&lock_db_cache, (byte*) opt);
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}


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/* Database options hash */
static HASH dboptions;
static my_bool dboptions_init= 0;
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static rw_lock_t LOCK_dboptions;
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/* Structure for database options */
typedef struct my_dbopt_st
{
  char *name;			/* Database name                  */
  uint name_length;		/* Database length name           */
  CHARSET_INFO *charset;	/* Database default character set */
} my_dbopt_t;

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/*
  Function we use in the creation of our hash to get key.
*/
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static byte* dboptions_get_key(my_dbopt_t *opt, uint *length,
                               my_bool not_used __attribute__((unused)))
{
  *length= opt->name_length;
  return (byte*) opt->name;
}


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/*
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  Helper function to write a query to binlog used by mysql_rm_db()
*/

static inline void write_to_binlog(THD *thd, char *query, uint q_len,
                                   char *db, uint db_len)
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{
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  Query_log_event qinfo(thd, query, q_len, 0, 0);
  qinfo.error_code= 0;
  qinfo.db= db;
  qinfo.db_len= db_len;
  mysql_bin_log.write(&qinfo);
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}  

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/*
  Function to free dboptions hash element
*/

static void free_dbopt(void *dbopt)
{
  my_free((gptr) dbopt, MYF(0));
}


/* 
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  Initialize database option hash and locked database hash.
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  SYNOPSIS
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    my_database_names()
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  NOTES
    Must be called before any other database function is called.

  RETURN
    0	ok
    1	Fatal error
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*/

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bool my_database_names_init(void)
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{
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  bool error= 0;
  (void) my_rwlock_init(&LOCK_dboptions, NULL);
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  if (!dboptions_init)
  {
    dboptions_init= 1;
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    error= hash_init(&dboptions, lower_case_table_names ? 
                     &my_charset_bin : system_charset_info,
                     32, 0, 0, (hash_get_key) dboptions_get_key,
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                     free_dbopt,0) ||
           hash_init(&lock_db_cache, lower_case_table_names ? 
                     &my_charset_bin : system_charset_info,
                     32, 0, 0, (hash_get_key) lock_db_get_key,
                     lock_db_free_element,0);

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  }
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  return error;
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}


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/* 
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  Free database option hash and locked databases hash.
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*/
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void my_database_names_free(void)
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{
  if (dboptions_init)
  {
    dboptions_init= 0;
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    hash_free(&dboptions);
    (void) rwlock_destroy(&LOCK_dboptions);
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    hash_free(&lock_db_cache);
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  }
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}


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/*
  Cleanup cached options
*/

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void my_dbopt_cleanup(void)
{
  rw_wrlock(&LOCK_dboptions);
  hash_free(&dboptions);
  hash_init(&dboptions, lower_case_table_names ? 
            &my_charset_bin : system_charset_info,
            32, 0, 0, (hash_get_key) dboptions_get_key,
            free_dbopt,0);
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  rw_unlock(&LOCK_dboptions);
}


/*
  Find database options in the hash.
  
  DESCRIPTION
    Search a database options in the hash, usings its path.
    Fills "create" on success.
  
  RETURN VALUES
    0 on success.
    1 on error.
*/

static my_bool get_dbopt(const char *dbname, HA_CREATE_INFO *create)
{
  my_dbopt_t *opt;
  uint length;
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  my_bool error= 1;
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  length= (uint) strlen(dbname);
  
  rw_rdlock(&LOCK_dboptions);
  if ((opt= (my_dbopt_t*) hash_search(&dboptions, (byte*) dbname, length)))
  {
    create->default_table_charset= opt->charset;
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    error= 0;
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  }
  rw_unlock(&LOCK_dboptions);
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  return error;
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}


/*
  Writes database options into the hash.
  
  DESCRIPTION
    Inserts database options into the hash, or updates
    options if they are already in the hash.
  
  RETURN VALUES
    0 on success.
    1 on error.
*/

static my_bool put_dbopt(const char *dbname, HA_CREATE_INFO *create)
{
  my_dbopt_t *opt;
  uint length;
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  my_bool error= 0;
  DBUG_ENTER("put_dbopt");

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  length= (uint) strlen(dbname);
  
  rw_wrlock(&LOCK_dboptions);
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  if (!(opt= (my_dbopt_t*) hash_search(&dboptions, (byte*) dbname, length)))
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  { 
    /* Options are not in the hash, insert them */
    char *tmp_name;
    if (!my_multi_malloc(MYF(MY_WME | MY_ZEROFILL),
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                         &opt, (uint) sizeof(*opt), &tmp_name, length+1,
                         NullS))
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    {
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      error= 1;
      goto end;
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    }
    
    opt->name= tmp_name;
    strmov(opt->name, dbname);
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    opt->name_length= length;
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    if ((error= my_hash_insert(&dboptions, (byte*) opt)))
    {
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      my_free((gptr) opt, MYF(0));
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      goto end;
    }
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  }

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  /* Update / write options in hash */
  opt->charset= create->default_table_charset;

end:
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  rw_unlock(&LOCK_dboptions);  
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  DBUG_RETURN(error);
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}


/*
  Deletes database options from the hash.
*/

void del_dbopt(const char *path)
{
  my_dbopt_t *opt;
  rw_wrlock(&LOCK_dboptions);
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  if ((opt= (my_dbopt_t *)hash_search(&dboptions, (const byte*) path,
                                      strlen(path))))
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    hash_delete(&dboptions, (byte*) opt);
  rw_unlock(&LOCK_dboptions);
}


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/*
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  Create database options file:

  DESCRIPTION
    Currently database default charset is only stored there.

  RETURN VALUES
  0	ok
  1	Could not create file or write to it.  Error sent through my_error()
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*/

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static bool write_db_opt(THD *thd, const char *path, HA_CREATE_INFO *create)
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{
  register File file;
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  char buf[256]; // Should be enough for one option
  bool error=1;
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  if (!create->default_table_charset)
    create->default_table_charset= thd->variables.collation_server;
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  if (put_dbopt(path, create))
    return 1;
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  if ((file=my_create(path, CREATE_MODE,O_RDWR | O_TRUNC,MYF(MY_WME))) >= 0)
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  {
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    ulong length;
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    length= (ulong) (strxnmov(buf, sizeof(buf)-1, "default-character-set=",
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                              create->default_table_charset->csname,
                              "\ndefault-collation=",
                              create->default_table_charset->name,
                              "\n", NullS) - buf);
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    /* Error is written by my_write */
    if (!my_write(file,(byte*) buf, length, MYF(MY_NABP+MY_WME)))
      error=0;
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    my_close(file,MYF(0));
  }
  return error;
}


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/*
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  Load database options file
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  load_db_opt()
  path		Path for option file
  create	Where to store the read options

  DESCRIPTION
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  RETURN VALUES
  0	File found
  1	No database file or could not open it
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*/

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bool load_db_opt(THD *thd, const char *path, HA_CREATE_INFO *create)
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{
  File file;
  char buf[256];
  DBUG_ENTER("load_db_opt");
  bool error=1;
  uint nbytes;

  bzero((char*) create,sizeof(*create));
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  create->default_table_charset= thd->variables.collation_server;
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  /* Check if options for this database are already in the hash */
  if (!get_dbopt(path, create))
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    DBUG_RETURN(0);

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  /* Otherwise, load options from the .opt file */
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  if ((file=my_open(path, O_RDONLY | O_SHARE, MYF(0))) < 0)
    goto err1;

  IO_CACHE cache;
  if (init_io_cache(&cache, file, IO_SIZE, READ_CACHE, 0, 0, MYF(0)))
    goto err2;
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  while ((int) (nbytes= my_b_gets(&cache, (char*) buf, sizeof(buf))) > 0)
  {
    char *pos= buf+nbytes-1;
    /* Remove end space and control characters */
    while (pos > buf && !my_isgraph(&my_charset_latin1, pos[-1]))
      pos--;
    *pos=0;
    if ((pos= strchr(buf, '=')))
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    {
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      if (!strncmp(buf,"default-character-set", (pos-buf)))
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      {
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        /*
           Try character set name, and if it fails
           try collation name, probably it's an old
           4.1.0 db.opt file, which didn't have
           separate default-character-set and
           default-collation commands.
        */
        if (!(create->default_table_charset=
        get_charset_by_csname(pos+1, MY_CS_PRIMARY, MYF(0))) &&
            !(create->default_table_charset=
              get_charset_by_name(pos+1, MYF(0))))
        {
          sql_print_error("Error while loading database options: '%s':",path);
          sql_print_error(ER(ER_UNKNOWN_CHARACTER_SET),pos+1);
          create->default_table_charset= default_charset_info;
        }
      }
      else if (!strncmp(buf,"default-collation", (pos-buf)))
      {
        if (!(create->default_table_charset= get_charset_by_name(pos+1,
                                                           MYF(0))))
        {
          sql_print_error("Error while loading database options: '%s':",path);
          sql_print_error(ER(ER_UNKNOWN_COLLATION),pos+1);
          create->default_table_charset= default_charset_info;
        }
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      }
    }
  }
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  /*
    Put the loaded value into the hash.
    Note that another thread could've added the same
    entry to the hash after we called get_dbopt(),
    but it's not an error, as put_dbopt() takes this
    possibility into account.
  */
  error= put_dbopt(path, create);

  end_io_cache(&cache);
err2:
  my_close(file,MYF(0));
err1:
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  DBUG_RETURN(error);
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}

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/*
  Retrieve database options by name. Load database options file or fetch from
  cache.

  SYNOPSIS
    load_db_opt_by_name()
    db_name         Database name
    db_create_info  Where to store the database options

  DESCRIPTION
    load_db_opt_by_name() is a shortcut for load_db_opt().

  NOTE
    Although load_db_opt_by_name() (and load_db_opt()) returns status of
    the operation, it is useless usually and should be ignored. The problem
    is that there are 1) system databases ("mysql") and 2) virtual
    databases ("information_schema"), which do not contain options file.
    So, load_db_opt[_by_name]() returns FALSE for these databases, but this
    is not an error.

    load_db_opt[_by_name]() clears db_create_info structure in any case, so
    even on failure it contains valid data. So, common use case is just
    call load_db_opt[_by_name]() without checking return value and use
    db_create_info right after that.

  RETURN VALUES (read NOTE!)
    FALSE   Success
    TRUE    Failed to retrieve options
*/

bool load_db_opt_by_name(THD *thd, const char *db_name,
                         HA_CREATE_INFO *db_create_info)
{
  char db_opt_path[FN_REFLEN];

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  /*
    Pass an empty file name, and the database options file name as extension
    to avoid table name to file name encoding.
  */
  (void) build_table_filename(db_opt_path, sizeof(db_opt_path),
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                              db_name, "", MY_DB_OPT_FILE, 0);
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  return load_db_opt(thd, db_opt_path, db_create_info);
}


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/*
  Create a database

  SYNOPSIS
  mysql_create_db()
  thd		Thread handler
  db		Name of database to create
		Function assumes that this is already validated.
  create_info	Database create options (like character set)
  silent	Used by replication when internally creating a database.
		In this case the entry should not be logged.

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  SIDE-EFFECTS
   1. Report back to client that command succeeded (send_ok)
   2. Report errors to client
   3. Log event to binary log
   (The 'silent' flags turns off 1 and 3.)

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  RETURN VALUES
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  FALSE ok
  TRUE  Error
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*/

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bool mysql_create_db(THD *thd, char *db, HA_CREATE_INFO *create_info,
                     bool silent)
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{
  char	 path[FN_REFLEN+16];
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  char	 tmp_query[FN_REFLEN+16];
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  long result= 1;
  int error= 0;
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  MY_STAT stat_info;
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  uint create_options= create_info ? create_info->options : 0;
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  uint path_len;
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  DBUG_ENTER("mysql_create_db");
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  /* do not create 'information_schema' db */
  if (!my_strcasecmp(system_charset_info, db, information_schema_name.str))
  {
    my_error(ER_DB_CREATE_EXISTS, MYF(0), db);
    DBUG_RETURN(-1);
  }
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  /*
    Do not create database if another thread is holding read lock.
    Wait for global read lock before acquiring LOCK_mysql_create_db.
    After wait_if_global_read_lock() we have protection against another
    global read lock. If we would acquire LOCK_mysql_create_db first,
    another thread could step in and get the global read lock before we
    reach wait_if_global_read_lock(). If this thread tries the same as we
    (admin a db), it would then go and wait on LOCK_mysql_create_db...
    Furthermore wait_if_global_read_lock() checks if the current thread
    has the global read lock and refuses the operation with
    ER_CANT_UPDATE_WITH_READLOCK if applicable.
  */
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  if (wait_if_global_read_lock(thd, 0, 1))
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  {
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    error= -1;
    goto exit2;
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  }
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  VOID(pthread_mutex_lock(&LOCK_mysql_create_db));

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  /* Check directory */
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  path_len= build_table_filename(path, sizeof(path), db, "", "", 0);
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  path[path_len-1]= 0;                    // Remove last '/' from path
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  if (my_stat(path,&stat_info,MYF(0)))
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  {
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    if (!(create_options & HA_LEX_CREATE_IF_NOT_EXISTS))
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    {
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      my_error(ER_DB_CREATE_EXISTS, MYF(0), db);
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      error= -1;
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      goto exit;
    }
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    push_warning_printf(thd, MYSQL_ERROR::WARN_LEVEL_NOTE,
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			ER_DB_CREATE_EXISTS, ER(ER_DB_CREATE_EXISTS), db);
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    if (!silent)
      send_ok(thd);
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    error= 0;
    goto exit;
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  }
  else
  {
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    if (my_errno != ENOENT)
    {
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      my_error(EE_STAT, MYF(0), path, my_errno);
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      goto exit;
    }
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    if (my_mkdir(path,0777,MYF(0)) < 0)
    {
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      my_error(ER_CANT_CREATE_DB, MYF(0), db, my_errno);
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      error= -1;
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      goto exit;
    }
  }
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  path[path_len-1]= FN_LIBCHAR;
  strmake(path+path_len, MY_DB_OPT_FILE, sizeof(path)-path_len-1);
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  if (write_db_opt(thd, path, create_info))
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  {
    /*
      Could not create options file.
      Restore things to beginning.
    */
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    path[path_len]= 0;
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    if (rmdir(path) >= 0)
    {
      error= -1;
      goto exit;
    }
    /*
      We come here when we managed to create the database, but not the option
      file.  In this case it's best to just continue as if nothing has
      happened.  (This is a very unlikely senario)
    */
  }
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  if (!silent)
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  {
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    char *query;
    uint query_length;

    if (!thd->query)				// Only in replication
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    {
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      query= 	     tmp_query;
      query_length= (uint) (strxmov(tmp_query,"create database `",
                                    db, "`", NullS) - tmp_query);
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    }
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    else
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    {
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      query= 	    thd->query;
      query_length= thd->query_length;
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    }
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    ha_binlog_log_query(thd, 0, LOGCOM_CREATE_DB,
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                        query, query_length,
                        db, "");

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    if (mysql_bin_log.is_open())
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    {
685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707
      Query_log_event qinfo(thd, query, query_length, 0, 
			    /* suppress_use */ TRUE);

      /*
	Write should use the database being created as the "current
        database" and not the threads current database, which is the
        default. If we do not change the "current database" to the
        database being created, the CREATE statement will not be
        replicated when using --binlog-do-db to select databases to be
        replicated. 

	An example (--binlog-do-db=sisyfos):
       
          CREATE DATABASE bob;        # Not replicated
          USE bob;                    # 'bob' is the current database
          CREATE DATABASE sisyfos;    # Not replicated since 'bob' is
                                      # current database.
          USE sisyfos;                # Will give error on slave since
                                      # database does not exist.
      */
      qinfo.db     = db;
      qinfo.db_len = strlen(db);

708
      mysql_bin_log.write(&qinfo);
709
    }
710
    send_ok(thd, result);
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711
  }
712

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713
exit:
714
  VOID(pthread_mutex_unlock(&LOCK_mysql_create_db));
715 716
  start_waiting_global_read_lock(thd);
exit2:
717
  DBUG_RETURN(error);
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718 719 720
}


721 722
/* db-name is already validated when we come here */

723
bool mysql_alter_db(THD *thd, const char *db, HA_CREATE_INFO *create_info)
724
{
725
  char path[FN_REFLEN+16];
726
  long result=1;
727
  int error= 0;
728
  DBUG_ENTER("mysql_alter_db");
729

730 731 732 733 734 735 736 737 738 739 740 741
  /*
    Do not alter database if another thread is holding read lock.
    Wait for global read lock before acquiring LOCK_mysql_create_db.
    After wait_if_global_read_lock() we have protection against another
    global read lock. If we would acquire LOCK_mysql_create_db first,
    another thread could step in and get the global read lock before we
    reach wait_if_global_read_lock(). If this thread tries the same as we
    (admin a db), it would then go and wait on LOCK_mysql_create_db...
    Furthermore wait_if_global_read_lock() checks if the current thread
    has the global read lock and refuses the operation with
    ER_CANT_UPDATE_WITH_READLOCK if applicable.
  */
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742
  if ((error=wait_if_global_read_lock(thd,0,1)))
743
    goto exit2;
744

745 746
  VOID(pthread_mutex_lock(&LOCK_mysql_create_db));

747 748 749 750 751
  /* 
     Recreate db options file: /dbpath/.db.opt
     We pass MY_DB_OPT_FILE as "extension" to avoid
     "table name to file name" encoding.
  */
752
  build_table_filename(path, sizeof(path), db, "", MY_DB_OPT_FILE, 0);
753
  if ((error=write_db_opt(thd, path, create_info)))
754 755
    goto exit;

756
  /*
757 758
     Change options if current database is being altered
     TODO: Delete this code
759 760 761
  */
  if (thd->db && !strcmp(thd->db,db))
  {
762 763
    thd->db_charset= create_info->default_table_charset ?
		     create_info->default_table_charset :
764
		     thd->variables.collation_server;
765
    thd->variables.collation_database= thd->db_charset;
766 767
  }

768
  ha_binlog_log_query(thd, 0, LOGCOM_ALTER_DB,
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769 770 771
                      thd->query, thd->query_length,
                      db, "");

772
  if (mysql_bin_log.is_open())
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773
  {
774
    Query_log_event qinfo(thd, thd->query, thd->query_length, 0,
775 776
			  /* suppress_use */ TRUE);

777 778 779 780 781
    /*
      Write should use the database being created as the "current
      database" and not the threads current database, which is the
      default.
    */
782 783 784
    qinfo.db     = db;
    qinfo.db_len = strlen(db);

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    thd->clear_error();
786
    mysql_bin_log.write(&qinfo);
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787
  }
788
  send_ok(thd, result);
789

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790
exit:
791
  VOID(pthread_mutex_unlock(&LOCK_mysql_create_db));
792 793
  start_waiting_global_read_lock(thd);
exit2:
794
  DBUG_RETURN(error);
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795 796 797
}


798
/*
799
  Drop all tables in a database and the database itself
800

801 802 803 804
  SYNOPSIS
    mysql_rm_db()
    thd			Thread handle
    db			Database name in the case given by user
805 806
		        It's already validated and set to lower case
                        (if needed) when we come here
807 808 809 810
    if_exists		Don't give error if database doesn't exists
    silent		Don't generate errors

  RETURN
811 812
    FALSE ok (Database dropped)
    ERROR Error
813
*/
814

815
bool mysql_rm_db(THD *thd,char *db,bool if_exists, bool silent)
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816 817
{
  long deleted=0;
818
  int error= 0;
819
  char	path[FN_REFLEN+16];
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820
  MY_DIR *dirp;
821
  uint length;
822
  TABLE_LIST* dropped_tables= 0;
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823 824
  DBUG_ENTER("mysql_rm_db");

825 826 827 828 829 830 831 832 833 834 835 836
  /*
    Do not drop database if another thread is holding read lock.
    Wait for global read lock before acquiring LOCK_mysql_create_db.
    After wait_if_global_read_lock() we have protection against another
    global read lock. If we would acquire LOCK_mysql_create_db first,
    another thread could step in and get the global read lock before we
    reach wait_if_global_read_lock(). If this thread tries the same as we
    (admin a db), it would then go and wait on LOCK_mysql_create_db...
    Furthermore wait_if_global_read_lock() checks if the current thread
    has the global read lock and refuses the operation with
    ER_CANT_UPDATE_WITH_READLOCK if applicable.
  */
837
  if (wait_if_global_read_lock(thd, 0, 1))
838 839 840 841
  {
    error= -1;
    goto exit2;
  }
842

843 844
  VOID(pthread_mutex_lock(&LOCK_mysql_create_db));

845
  length= build_table_filename(path, sizeof(path), db, "", "", 0);
846 847 848 849
  strmov(path+length, MY_DB_OPT_FILE);		// Append db option file name
  del_dbopt(path);				// Remove dboption hash entry
  path[length]= '\0';				// Remove file name

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850
  /* See if the directory exists */
851
  if (!(dirp= my_dir(path,MYF(MY_DONT_SORT))))
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852
  {
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853
    if (!if_exists)
854
    {
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855
      error= -1;
856
      my_error(ER_DB_DROP_EXISTS, MYF(0), db);
857
      goto exit;
858
    }
859
    else
860 861
      push_warning_printf(thd, MYSQL_ERROR::WARN_LEVEL_NOTE,
			  ER_DB_DROP_EXISTS, ER(ER_DB_DROP_EXISTS), db);
862 863 864 865 866 867
  }
  else
  {
    pthread_mutex_lock(&LOCK_open);
    remove_db_from_cache(db);
    pthread_mutex_unlock(&LOCK_open);
868

869
    
870
    error= -1;
871
    if ((deleted= mysql_rm_known_files(thd, dirp, db, path, 0,
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872
                                       &dropped_tables)) >= 0)
873 874
    {
      ha_drop_database(path);
875
      query_cache_invalidate1(db);
876
      error = 0;
877
    }
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878
  }
879
  if (!silent && deleted>=0)
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880
  {
881 882 883
    const char *query;
    ulong query_length;
    if (!thd->query)
884
    {
885 886 887 888 889 890 891 892 893 894 895 896
      /* The client used the old obsolete mysql_drop_db() call */
      query= path;
      query_length= (uint) (strxmov(path, "drop database `", db, "`",
                                     NullS) - path);
    }
    else
    {
      query =thd->query;
      query_length= thd->query_length;
    }
    if (mysql_bin_log.is_open())
    {
897 898
      Query_log_event qinfo(thd, query, query_length, 0, 
			    /* suppress_use */ TRUE);
899 900 901 902 903
      /*
        Write should use the database being created as the "current
        database" and not the threads current database, which is the
        default.
      */
904 905 906
      qinfo.db     = db;
      qinfo.db_len = strlen(db);

907 908
      thd->clear_error();
      mysql_bin_log.write(&qinfo);
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909
    }
910
    thd->server_status|= SERVER_STATUS_DB_DROPPED;
911
    send_ok(thd, (ulong) deleted);
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912
    thd->server_status&= ~SERVER_STATUS_DB_DROPPED;
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913
  }
914
  else if (mysql_bin_log.is_open())
915
  {
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916 917 918 919 920 921
    char *query, *query_pos, *query_end, *query_data_start;
    TABLE_LIST *tbl;
    uint db_len;

    if (!(query= thd->alloc(MAX_DROP_TABLE_Q_LEN)))
      goto exit; /* not much else we can do */
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922
    query_pos= query_data_start= strmov(query,"drop table ");
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923 924
    query_end= query + MAX_DROP_TABLE_Q_LEN;
    db_len= strlen(db);
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925

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926
    for (tbl= dropped_tables; tbl; tbl= tbl->next_local)
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927 928
    {
      uint tbl_name_len;
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929 930

      /* 3 for the quotes and the comma*/
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931
      tbl_name_len= strlen(tbl->table_name) + 3;
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932 933 934 935
      if (query_pos + tbl_name_len + 1 >= query_end)
      {
        write_to_binlog(thd, query, query_pos -1 - query, db, db_len);
        query_pos= query_data_start;
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936 937
      }

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938
      *query_pos++ = '`';
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939
      query_pos= strmov(query_pos,tbl->table_name);
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940 941 942
      *query_pos++ = '`';
      *query_pos++ = ',';
    }
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943

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944 945 946 947
    if (query_pos != query_data_start)
    {
      write_to_binlog(thd, query, query_pos -1 - query, db, db_len);
    }
948
  }
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949 950

exit:
951
  (void)sp_drop_db_routines(thd, db); /* QQ Ignore errors for now  */
952
  Events::get_instance()->drop_schema_events(thd, db);
953
  /*
954 955 956 957
    If this database was the client's selected database, we silently
    change the client's selected database to nothing (to have an empty
    SELECT DATABASE() in the future). For this we free() thd->db and set
    it to 0.
958
  */
959
  if (thd->db && !strcmp(thd->db, db))
960
    thd->set_db(NULL, 0);
961
  VOID(pthread_mutex_unlock(&LOCK_mysql_create_db));
962 963
  start_waiting_global_read_lock(thd);
exit2:
964
  DBUG_RETURN(error);
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965 966 967 968
}

/*
  Removes files with known extensions plus all found subdirectories that
969
  are 2 hex digits (raid directories).
970
  thd MUST be set when calling this function!
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971 972
*/

973
static long mysql_rm_known_files(THD *thd, MY_DIR *dirp, const char *db,
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974 975
				 const char *org_path, uint level,
                                 TABLE_LIST **dropped_tables)
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976 977 978 979
{
  long deleted=0;
  ulong found_other_files=0;
  char filePath[FN_REFLEN];
980
  TABLE_LIST *tot_list=0, **tot_list_next;
981
  List<String> raid_dirs;
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982
  DBUG_ENTER("mysql_rm_known_files");
983
  DBUG_PRINT("enter",("path: %s", org_path));
984 985

  tot_list_next= &tot_list;
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986

987
  for (uint idx=0 ;
988
       idx < (uint) dirp->number_off_files && !thd->killed ;
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989 990 991
       idx++)
  {
    FILEINFO *file=dirp->dir_entry+idx;
992
    char *extension;
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993 994
    DBUG_PRINT("info",("Examining: %s", file->name));

995 996 997 998 999
    /* skiping . and .. */
    if (file->name[0] == '.' && (!file->name[1] ||
       (file->name[1] == '.' &&  !file->name[2])))
      continue;

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1000
    /* Check if file is a raid directory */
1001
    if ((my_isdigit(system_charset_info, file->name[0]) ||
1002
	 (file->name[0] >= 'a' && file->name[0] <= 'f')) &&
1003
	(my_isdigit(system_charset_info, file->name[1]) ||
1004
	 (file->name[1] >= 'a' && file->name[1] <= 'f')) &&
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1005 1006
	!file->name[2] && !level)
    {
1007
      char newpath[FN_REFLEN], *copy_of_path;
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1008
      MY_DIR *new_dirp;
1009
      String *dir;
1010
      uint length;
1011

1012
      strxmov(newpath,org_path,"/",file->name,NullS);
1013
      length= unpack_filename(newpath,newpath);
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1014 1015 1016
      if ((new_dirp = my_dir(newpath,MYF(MY_DONT_SORT))))
      {
	DBUG_PRINT("my",("New subdir found: %s", newpath));
1017
	if ((mysql_rm_known_files(thd, new_dirp, NullS, newpath,1,0)) < 0)
1018 1019
	  goto err;
	if (!(copy_of_path= thd->memdup(newpath, length+1)) ||
1020
	    !(dir= new (thd->mem_root) String(copy_of_path, length,
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1021
					       &my_charset_bin)) ||
1022 1023
	    raid_dirs.push_back(dir))
	  goto err;
1024
	continue;
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1025
      }
1026
      found_other_files++;
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1027 1028
      continue;
    }
1029 1030 1031 1032
    else if (file->name[0] == 'a' && file->name[1] == 'r' &&
             file->name[2] == 'c' && file->name[3] == '\0')
    {
      /* .frm archive */
1033
      char newpath[FN_REFLEN];
1034 1035
      MY_DIR *new_dirp;
      strxmov(newpath, org_path, "/", "arc", NullS);
1036
      (void) unpack_filename(newpath, newpath);
1037 1038 1039 1040 1041 1042 1043 1044 1045 1046
      if ((new_dirp = my_dir(newpath, MYF(MY_DONT_SORT))))
      {
	DBUG_PRINT("my",("Archive subdir found: %s", newpath));
	if ((mysql_rm_arc_files(thd, new_dirp, newpath)) < 0)
	  goto err;
	continue;
      }
      found_other_files++;
      continue;
    }
1047 1048
    if (!(extension= strrchr(file->name, '.')))
      extension= strend(file->name);
1049
    if (find_type(extension, &deletable_extentions,1+2) <= 0)
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1050
    {
1051
      if (find_type(extension, ha_known_exts(),1+2) <= 0)
1052
	found_other_files++;
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1053 1054
      continue;
    }
1055
    /* just for safety we use files_charset_info */
1056
    if (db && !my_strcasecmp(files_charset_info,
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1057
                             extension, reg_ext))
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1058
    {
1059
      /* Drop the table nicely */
1060
      *extension= 0;			// Remove extension
1061
      TABLE_LIST *table_list=(TABLE_LIST*)
1062
	thd->calloc(sizeof(*table_list)+ strlen(db)+strlen(file->name)+2);
1063
      if (!table_list)
1064
	goto err;
1065
      table_list->db= (char*) (table_list+1);
1066 1067 1068
      table_list->table_name= strmov(table_list->db, db) + 1;
      VOID(filename_to_tablename(file->name, table_list->table_name,
                                 strlen(file->name) + 1));
1069
      table_list->alias= table_list->table_name;	// If lower_case_table_names=2
1070 1071
      /* Link into list */
      (*tot_list_next)= table_list;
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1072
      tot_list_next= &table_list->next_local;
1073
      deleted++;
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1074
    }
1075 1076
    else
    {
1077
      strxmov(filePath, org_path, "/", file->name, NullS);
1078 1079
      if (my_delete_with_symlink(filePath,MYF(MY_WME)))
      {
1080
	goto err;
1081 1082 1083
      }
    }
  }
1084
  if (thd->killed ||
1085
      (tot_list && mysql_rm_table_part2_with_lock(thd, tot_list, 1, 0, 1)))
1086 1087 1088
    goto err;

  /* Remove RAID directories */
1089
  {
1090 1091
    List_iterator<String> it(raid_dirs);
    String *dir;
1092
    while ((dir= it++))
1093 1094
      if (rmdir(dir->c_ptr()) < 0)
	found_other_files++;
1095
  }
1096 1097
  my_dirend(dirp);  
  
1098 1099 1100
  if (dropped_tables)
    *dropped_tables= tot_list;
  
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1101 1102 1103 1104
  /*
    If the directory is a symbolic link, remove the link first, then
    remove the directory the symbolic link pointed at
  */
1105 1106
  if (found_other_files)
  {
1107
    my_error(ER_DB_DROP_RMDIR, MYF(0), org_path, EEXIST);
1108 1109 1110
    DBUG_RETURN(-1);
  }
  else
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1111
  {
1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138
    /* Don't give errors if we can't delete 'RAID' directory */
    if (rm_dir_w_symlink(org_path, level == 0))
      DBUG_RETURN(-1);
  }

  DBUG_RETURN(deleted);

err:
  my_dirend(dirp);
  DBUG_RETURN(-1);
}


/*
  Remove directory with symlink

  SYNOPSIS
    rm_dir_w_symlink()
    org_path    path of derictory
    send_error  send errors
  RETURN
    0 OK
    1 ERROR
*/

static my_bool rm_dir_w_symlink(const char *org_path, my_bool send_error)
{
1139
  char tmp_path[FN_REFLEN], *pos;
1140 1141 1142
  char *path= tmp_path;
  DBUG_ENTER("rm_dir_w_symlink");
  unpack_filename(tmp_path, org_path);
1143
#ifdef HAVE_READLINK
1144
  int error;
1145
  char tmp2_path[FN_REFLEN];
1146

1147 1148 1149 1150 1151 1152 1153 1154 1155 1156
  /* Remove end FN_LIBCHAR as this causes problem on Linux in readlink */
  pos= strend(path);
  if (pos > path && pos[-1] == FN_LIBCHAR)
    *--pos=0;

  if ((error= my_readlink(tmp2_path, path, MYF(MY_WME))) < 0)
    DBUG_RETURN(1);
  if (!error)
  {
    if (my_delete(path, MYF(send_error ? MY_WME : 0)))
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1157
    {
1158
      DBUG_RETURN(send_error);
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1159
    }
1160 1161 1162
    /* Delete directory symbolic link pointed at */
    path= tmp2_path;
  }
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1163
#endif
1164 1165
  /* Remove last FN_LIBCHAR to not cause a problem on OS/2 */
  pos= strend(path);
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1166

1167 1168 1169 1170
  if (pos > path && pos[-1] == FN_LIBCHAR)
    *--pos=0;
  if (rmdir(path) < 0 && send_error)
  {
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    my_error(ER_DB_DROP_RMDIR, MYF(0), path, errno);
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    DBUG_RETURN(1);
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  }
  DBUG_RETURN(0);
}


/*
  Remove .frm archives from directory

  SYNOPSIS
    thd       thread handler
    dirp      list of files in archive directory
    db        data base name
    org_path  path of archive directory

  RETURN
    > 0 number of removed files
    -1  error
*/
static long mysql_rm_arc_files(THD *thd, MY_DIR *dirp,
				 const char *org_path)
{
  long deleted= 0;
  ulong found_other_files= 0;
  char filePath[FN_REFLEN];
  DBUG_ENTER("mysql_rm_arc_files");
  DBUG_PRINT("enter", ("path: %s", org_path));

  for (uint idx=0 ;
       idx < (uint) dirp->number_off_files && !thd->killed ;
       idx++)
  {
    FILEINFO *file=dirp->dir_entry+idx;
    char *extension, *revision;
    DBUG_PRINT("info",("Examining: %s", file->name));

    /* skiping . and .. */
    if (file->name[0] == '.' && (!file->name[1] ||
       (file->name[1] == '.' &&  !file->name[2])))
      continue;

    extension= fn_ext(file->name);
    if (extension[0] != '.' ||
        extension[1] != 'f' || extension[2] != 'r' ||
        extension[3] != 'm' || extension[4] != '-')
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    {
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      found_other_files++;
      continue;
    }
    revision= extension+5;
    while (*revision && my_isdigit(system_charset_info, *revision))
      revision++;
    if (*revision)
    {
      found_other_files++;
      continue;
    }
    strxmov(filePath, org_path, "/", file->name, NullS);
    if (my_delete_with_symlink(filePath,MYF(MY_WME)))
    {
      goto err;
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    }
  }
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  if (thd->killed)
    goto err;

  my_dirend(dirp);

  /*
    If the directory is a symbolic link, remove the link first, then
    remove the directory the symbolic link pointed at
  */
  if (!found_other_files &&
      rm_dir_w_symlink(org_path, 0))
    DBUG_RETURN(-1);
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  DBUG_RETURN(deleted);
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err:
  my_dirend(dirp);
  DBUG_RETURN(-1);
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}


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/*
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  Change the current database.
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  SYNOPSIS
    mysql_change_db()
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    thd			thread handle
    name		database name
    no_access_check	if TRUE, don't do access check. In this
                        case name may be ""
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  DESCRIPTION
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    Check that the database name corresponds to a valid and
    existent database, check access rights (unless called with
    no_access_check), and set the current database. This function
    is called to change the current database upon user request
    (COM_CHANGE_DB command) or temporarily, to execute a stored
    routine.
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  NOTES
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    This function is not the only way to switch the database that
    is currently employed. When the replication slave thread
    switches the database before executing a query, it calls
    thd->set_db directly. However, if the query, in turn, uses
    a stored routine, the stored routine will use this function,
    even if it's run on the slave.

    This function allocates the name of the database on the system
    heap: this is necessary to be able to uniformly change the
    database from any module of the server. Up to 5.0 different
    modules were using different memory to store the name of the
    database, and this led to memory corruption: a stack pointer
    set by Stored Procedures was used by replication after the
    stack address was long gone.

    This function does not send anything, including error
    messages, to the client. If that should be sent to the client,
    call net_send_error after this function.
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  RETURN VALUES
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    0	OK
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    1	error
*/

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bool mysql_change_db(THD *thd, const char *name, bool no_access_check)
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{
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  int path_length, db_length;
  char *db_name;
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  bool system_db= 0;
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#ifndef NO_EMBEDDED_ACCESS_CHECKS
  ulong db_access;
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  Security_context *sctx= thd->security_ctx;
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  LINT_INIT(db_access);
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#endif
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  DBUG_ENTER("mysql_change_db");
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  DBUG_PRINT("enter",("name: '%s'",name));
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  if (name == NULL || name[0] == '\0' && no_access_check == FALSE)
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  {
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    my_message(ER_NO_DB_ERROR, ER(ER_NO_DB_ERROR), MYF(0));
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    DBUG_RETURN(1);				/* purecov: inspected */
  }
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  else if (name[0] == '\0')
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  {
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    /* Called from SP to restore the original database, which was NULL */
    DBUG_ASSERT(no_access_check);
    system_db= 1;
    db_name= NULL;
    db_length= 0;
    goto end;
  }
  /*
    Now we need to make a copy because check_db_name requires a
    non-constant argument. TODO: fix check_db_name.
  */
  if ((db_name= my_strdup(name, MYF(MY_WME))) == NULL)
    DBUG_RETURN(1);                             /* the error is set */
  db_length= strlen(db_name);
  if (check_db_name(db_name))
  {
    my_error(ER_WRONG_DB_NAME, MYF(0), db_name);
    my_free(db_name, MYF(0));
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    DBUG_RETURN(1);
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  }
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  DBUG_PRINT("info",("Use database: %s", db_name));
  if (!my_strcasecmp(system_charset_info, db_name, information_schema_name.str))
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  {
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    system_db= 1;
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#ifndef NO_EMBEDDED_ACCESS_CHECKS
    db_access= SELECT_ACL;
#endif
    goto end;
  }

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#ifndef NO_EMBEDDED_ACCESS_CHECKS
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  if (!no_access_check)
  {
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    if (test_all_bits(sctx->master_access, DB_ACLS))
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      db_access=DB_ACLS;
    else
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      db_access= (acl_get(sctx->host, sctx->ip, sctx->priv_user, db_name, 0) |
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                  sctx->master_access);
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    if (!(db_access & DB_ACLS) && (!grant_option ||
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                                   check_grant_db(thd,db_name)))
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    {
      my_error(ER_DBACCESS_DENIED_ERROR, MYF(0),
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               sctx->priv_user,
               sctx->priv_host,
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               db_name);
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      general_log_print(thd, COM_INIT_DB, ER(ER_DBACCESS_DENIED_ERROR),
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                        sctx->priv_user, sctx->priv_host, db_name);
      my_free(db_name,MYF(0));
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      DBUG_RETURN(1);
    }
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  }
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#endif
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  if (check_db_dir_existence(db_name))
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  {
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    my_error(ER_BAD_DB_ERROR, MYF(0), db_name);
    my_free(db_name, MYF(0));
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    DBUG_RETURN(1);
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  }
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1378
end:
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  x_free(thd->db);
  DBUG_ASSERT(db_name == NULL || db_name[0] != '\0');
  thd->reset_db(db_name, db_length);            // THD::~THD will free this
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#ifndef NO_EMBEDDED_ACCESS_CHECKS
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  if (!no_access_check)
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    sctx->db_access= db_access;
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#endif
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  if (system_db)
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  {
    thd->db_charset= system_charset_info;
    thd->variables.collation_database= system_charset_info;
  }
  else
  {
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    HA_CREATE_INFO create;

    load_db_opt_by_name(thd, db_name, &create);

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    thd->db_charset= create.default_table_charset ?
      create.default_table_charset :
      thd->variables.collation_server;
    thd->variables.collation_database= thd->db_charset;
  }
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  DBUG_RETURN(0);
}
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static int
lock_databases(THD *thd, const char *db1, uint length1,
                         const char *db2, uint length2)
{
  pthread_mutex_lock(&LOCK_lock_db);
  while (!thd->killed &&
         (hash_search(&lock_db_cache,(byte*) db1, length1) ||
          hash_search(&lock_db_cache,(byte*) db2, length2)))
  {
    wait_for_condition(thd, &LOCK_lock_db, &COND_refresh);
    pthread_mutex_lock(&LOCK_lock_db);
  }

  if (thd->killed)
  {
    pthread_mutex_unlock(&LOCK_lock_db);
    return 1;
  }

  lock_db_insert(db1, length1);
  lock_db_insert(db2, length2);
  creating_database++;

  /*
    Wait if a concurent thread is creating a table at the same time.
    The assumption here is that it will not take too long until
    there is a point in time when a table is not created.
  */

  while (!thd->killed && creating_table)
  {
    wait_for_condition(thd, &LOCK_lock_db, &COND_refresh);
    pthread_mutex_lock(&LOCK_lock_db);
  }

  if (thd->killed)
  {
    lock_db_delete(db1, length1);
    lock_db_delete(db2, length2);
    creating_database--;
    pthread_mutex_unlock(&LOCK_lock_db);
    pthread_cond_signal(&COND_refresh);
    return(1);
  }

  /*
    We can unlock now as the hash will protect against anyone creating a table
    in the databases we are using
  */
  pthread_mutex_unlock(&LOCK_lock_db);
  return 0;
}


/*
  Rename database.

  SYNOPSIS
    mysql_rename_db()
    thd                 Thread handler
    olddb               Old database name
    newdb               New database name

  DESCRIPTION
   This function is invoked whenever a RENAME DATABASE query is executed:

     RENAME DATABASE 'olddb' TO 'newdb'.

  NOTES

    If we have managed to rename (move) tables to the new database
    but something failed on a later step, then we store the
    RENAME DATABASE event in the log. mysql_rename_db() is atomic in
    the sense that it will rename all or none of the tables.

  TODO:
    - Better trigger, stored procedure, event, grant handling,
      see the comments below.
      NOTE: It's probably a good idea to call wait_if_global_read_lock()
      once in mysql_rename_db(), instead of locking inside all
      the required functions for renaming triggerts, SP, events, grants, etc.

  RETURN VALUES
    0	ok
    1	error
*/


bool mysql_rename_db(THD *thd, LEX_STRING *old_db, LEX_STRING *new_db)
{
  int error= 0, change_to_newdb= 0;
  char path[FN_REFLEN+16];
  uint length;
  HA_CREATE_INFO create_info;
  MY_DIR *dirp;
  TABLE_LIST *table_list;
  SELECT_LEX *sl= thd->lex->current_select;
  DBUG_ENTER("mysql_rename_db");

  if (lock_databases(thd, old_db->str, old_db->length,
                          new_db->str, new_db->length))
    return 1;

  /*
    Let's remember if we should do "USE newdb" afterwards.
    thd->db will be cleared in mysql_rename_db()
  */
  if (thd->db && !strcmp(thd->db, old_db->str))
    change_to_newdb= 1;

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  build_table_filename(path, sizeof(path)-1,
                       old_db->str, "", MY_DB_OPT_FILE, 0);
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  if ((load_db_opt(thd, path, &create_info)))
    create_info.default_table_charset= thd->variables.collation_server;

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  length= build_table_filename(path, sizeof(path)-1, old_db->str, "", "", 0);
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  if (length && path[length-1] == FN_LIBCHAR)
    path[length-1]=0;                            // remove ending '\'
  if ((error= my_access(path,F_OK)))
  {
    my_error(ER_BAD_DB_ERROR, MYF(0), old_db->str);
    goto exit;
  }

  /* Step1: Create the new database */
  if ((error= mysql_create_db(thd, new_db->str, &create_info, 1)))
    goto exit;

  /* Step2: Move tables to the new database */
  if ((dirp = my_dir(path,MYF(MY_DONT_SORT))))
  {
    uint nfiles= (uint) dirp->number_off_files;
    for (uint idx=0 ; idx < nfiles && !thd->killed ; idx++)
    {
      FILEINFO *file= dirp->dir_entry + idx;
      char *extension, tname[FN_REFLEN];
      LEX_STRING table_str;
      DBUG_PRINT("info",("Examining: %s", file->name));

      /* skiping non-FRM files */
      if (my_strcasecmp(files_charset_info,
                        (extension= fn_rext(file->name)), reg_ext))
        continue;

      /* A frm file found, add the table info rename list */
      *extension= '\0';
      
      table_str.length= filename_to_tablename(file->name,
                                              tname, sizeof(tname)-1);
      table_str.str= sql_memdup(tname, table_str.length + 1);
      Table_ident *old_ident= new Table_ident(thd, *old_db, table_str, 0);
      Table_ident *new_ident= new Table_ident(thd, *new_db, table_str, 0);
      if (!old_ident || !new_ident ||
          !sl->add_table_to_list(thd, old_ident, NULL,
                                 TL_OPTION_UPDATING, TL_IGNORE) ||
          !sl->add_table_to_list(thd, new_ident, NULL,
                                 TL_OPTION_UPDATING, TL_IGNORE))
      {
        error= 1;
        my_dirend(dirp);
        goto exit;
      }
    }
    my_dirend(dirp);  
  }

  if ((table_list= thd->lex->query_tables) &&
      (error= mysql_rename_tables(thd, table_list, 1)))
  {
    /*
      Failed to move all tables from the old database to the new one.
      In the best case mysql_rename_tables() moved all tables back to the old
      database. In the worst case mysql_rename_tables() moved some tables
      to the new database, then failed, then started to move the tables back,  and
      then failed again. In this situation we have some tables in the
      old database and some tables in the new database.
      Let's delete the option file, and then the new database directory.
      If some tables were left in the new directory, rmdir() will fail.
      It garantees we never loose any tables.
    */
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    build_table_filename(path, sizeof(path)-1,
                         new_db->str,"",MY_DB_OPT_FILE, 0);
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    my_delete(path, MYF(MY_WME));
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    length= build_table_filename(path, sizeof(path)-1, new_db->str, "", "", 0);
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    if (length && path[length-1] == FN_LIBCHAR)
      path[length-1]=0;                            // remove ending '\'
    rmdir(path);
    goto exit;
  }


  /*
    Step3: move all remaining files to the new db's directory.
    Skip db opt file: it's been created by mysql_create_db() in
    the new directory, and will be dropped by mysql_rm_db() in the old one.
    Trigger TRN and TRG files are be moved as regular files at the moment,
    without any special treatment.

    Triggers without explicit database qualifiers in table names work fine: 
      use d1;
      create trigger trg1 before insert on t2 for each row set @a:=1
      rename database d1 to d2;

    TODO: Triggers, having the renamed database explicitely written
    in the table qualifiers.
    1. when the same database is renamed:
        create trigger d1.trg1 before insert on d1.t1 for each row set @a:=1;
        rename database d1 to d2;
      Problem: After database renaming, the trigger's body
               still points to the old database d1.
    2. when another database is renamed:
        create trigger d3.trg1 before insert on d3.t1 for each row
          insert into d1.t1 values (...);
        rename database d1 to d2;
      Problem: After renaming d1 to d2, the trigger's body
               in the database d3 still points to database d1.
  */

  if ((dirp = my_dir(path,MYF(MY_DONT_SORT))))
  {
    uint nfiles= (uint) dirp->number_off_files;
    for (uint idx=0 ; idx < nfiles ; idx++)
    {
      FILEINFO *file= dirp->dir_entry + idx;
      char oldname[FN_REFLEN], newname[FN_REFLEN];
      DBUG_PRINT("info",("Examining: %s", file->name));

      /* skiping . and .. and MY_DB_OPT_FILE */
      if ((file->name[0] == '.' &&
           (!file->name[1] || (file->name[1] == '.' && !file->name[2]))) ||
          !my_strcasecmp(files_charset_info, file->name, MY_DB_OPT_FILE))
        continue;

      /* pass empty file name, and file->name as extension to avoid encoding */
      build_table_filename(oldname, sizeof(oldname)-1,
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                           old_db->str, "", file->name, 0);
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      build_table_filename(newname, sizeof(newname)-1,
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                           new_db->str, "", file->name, 0);
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      my_rename(oldname, newname, MYF(MY_WME));
    }
    my_dirend(dirp);  
  }

  /*
    Step4: TODO: moving stored procedures in the 'proc' system table
    We need a new function: sp_move_db_routines(thd, olddb, newdb)
    Which will basically have the same effect with:
    UPDATE proc SET db='newdb' WHERE db='olddb'
    Note, for 5.0 to 5.1 upgrade purposes we don't really need it.

    The biggest problem here is that we can't have a lock on LOCK_open() while
    calling open_table() for 'proc'.

    Two solutions:
    - Start by opening the 'event' and 'proc' (and other) tables for write
      even before creating the 'to' database.  (This will have the nice
      effect of blocking another 'rename database' while the lock is active).
    - Use the solution "Disable create of new tables during lock table"

    For an example of how to read through all rows, see:
    sql_help.cc::search_topics()
  */

  /*
    Step5: TODO: moving events in the 'event' system table
    We need a new function evex_move_db_events(thd, olddb, newdb)
    Which will have the same effect with:
    UPDATE event SET db='newdb' WHERE db='olddb'
    Note, for 5.0 to 5.1 upgrade purposes we don't really need it.
  */

  /*
    Step6: TODO: moving grants in the 'db', 'tables_priv', 'columns_priv'.
    Update each grant table, doing the same with:
    UPDATE system_table SET db='newdb' WHERE db='olddb'
  */

  /*
    Step7: drop the old database.
    remove_db_from_cache(olddb) and query_cache_invalidate(olddb)
    are done inside mysql_rm_db(), no needs to execute them again.
    mysql_rm_db() also "unuses" if we drop the current database.
  */
  error= mysql_rm_db(thd, old_db->str, 0, 1);

  /* Step8: logging */
  if (mysql_bin_log.is_open())
  {
    Query_log_event qinfo(thd, thd->query, thd->query_length, 0, TRUE);
    thd->clear_error();
    mysql_bin_log.write(&qinfo);
  }

  /* Step9: Let's do "use newdb" if we renamed the current database */
  if (change_to_newdb)
    error|= mysql_change_db(thd, new_db->str, 0);

exit:
  pthread_mutex_lock(&LOCK_lock_db);
  /* Remove the databases from db lock cache */
  lock_db_delete(old_db->str, old_db->length);
  lock_db_delete(new_db->str, new_db->length);
  creating_database--;
  /* Signal waiting CREATE TABLE's to continue */
  pthread_cond_signal(&COND_refresh);
  pthread_mutex_unlock(&LOCK_lock_db);

  DBUG_RETURN(error);
}
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/*
  Check if there is directory for the database name.

  SYNOPSIS
    check_db_dir_existence()
    db_name   database name

  RETURN VALUES
    FALSE   There is directory for the specified database name.
    TRUE    The directory does not exist.
*/

bool check_db_dir_existence(const char *db_name)
{
  char db_dir_path[FN_REFLEN];
  uint db_dir_path_len;

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  db_dir_path_len= build_table_filename(db_dir_path, sizeof(db_dir_path),
1734
                                        db_name, "", "", 0);
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  if (db_dir_path_len && db_dir_path[db_dir_path_len - 1] == FN_LIBCHAR)
    db_dir_path[db_dir_path_len - 1]= 0;

  /* Check access. */

  return my_access(db_dir_path, F_OK);
}